1. Technical Field
The present disclosure relates to a lead frame and a method for manufacturing the same.
2. Related Art
In quad flat non-leaded (QFN) package semiconductor devices including a flip-chip connection structure, typically solder is used for bonding a semiconductor chip to a lead frame. Accordingly, the lead frame surface includes copper material or copper plating.
As in other semiconductor devices, the QFN package is also required to have high adhesion between the lead frame and a molding resin (which may be hereafter simply referred to as the “resin”) for increasing reliability.
As a means to achieve increased adhesion with the resin, a method referred to as black oxide treatment has been known. In this method, the lead frame is immersed in an oxidizing alkaline solution and the like so as to oxidize copper contained in the lead frame surface. In this way, a copper oxide film is formed on the lead frame surface. For example, JP-A-3-295262 describes an anode oxidizing method, where a resultant copper oxide film has high adhesion with a resin, ensuring high packaging reliability.